Looms



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LOOMS Filed March 25, 1967 Sheet 3 of :5

United States Patent 14,099/ 66 US. Cl. 139-12 Int. Cl. D03d 41/00, 47/00,- D031 I/22 16 Claims ABSTRACT OF THE DISCLOSURE A loom of the type in which two weft yarns are carried into a warp shed from opposite sides from stationary weft supplies thereof by reciprocated spears which follow each other across the warp shed and in which the warp threads are shedded progressively across the loom between the said spears as they pass between the warp threads so that the weft threads can be laid in different sheds wherein the spears are arcuate and reciprocated in an arcuate path about an axis which is substantially perpendicular to the plane of the mean position of the Warp shed at the fell along the arcuate path so that Weft threads inserted into the warp lie in the cloth in an arc.

This invention relates to looms of the general type of that forming the subject of our U.S. Patent No. 2,816,576, issued Dec. 17, 1957 (hereinafter referred to as a loom of the type described) in which two weft yarns are carried into the warp shed from opposite sides thereof by reciprocated spears which follow each other across the warp shed and in which the warp threads are shedded or crossed over progressively across the loom in the space between the said spears as they pass through the warp threads so that the weft yarns can be laid in different sheds. In the former specification means are pro vided at each selvedge for automatically severing loops of single weft pick laid in the Warp shed by the spears, and grippers are provided on the spears to enable them to carry severed ends of loops through the warp shed. In the latter specification double weft pick is laid and pins are provided at the selveges to form weft loops which are throttled by further weft yarn which is defleeted over the pins.

In the loom described in US. Patent No. 2,816,576 the two spears move in the shed in the same path or track in a straight line movement. While such a loorn has a very high production rate as compared with conventional looms employing shuttles its speed of operation is dependent on the speed of reciprocation of the spears and this depends on the weight of parts moving at the same speed as the spears.

With the loom described in detail in US. Patent No. 2,816,576 the parts moving at spear speed include the spears which are fairly lengthy as they have to traverse the width of the cloth to be woven, the chains used to drive the spears and the drive for the chains including chain wheels, carriages carrying the wheels and a crank and connecting rod to drive the carriages.

In a loom of the type described in accordance with this invention the spears which are arcuate are reciprocated in an arcuate path about an axis which is substantially perpendicular to the plane of the mean position of the warp shed at the fell along the arcuate path so that weft threads inserted into the warp lie in the cloth in an arc.

The arrangement of the parts of the loom may be made very compact with the supports for both the beam and 3,426,805 Patented Feb. 11, 1969 take-up roll located beneath the plane containing the spears or the like and these supports may be so arranged and driven that the cloth, when woven is moved away from an operator positioned at the front of the loom. This gives good access to the cloth during weaving.

Due to the arcuate arrangement the loom can occupy a smaller fioor space for a given Width of cloth than a straight line spear loom and further space economy can be achieved and the parts of the loom made more accessible, by positioning the spears and their arms at an angle to the horizontal of say 20.

Due to the arcuate path the spears may be driven by a drive comprising a radially extending arm for each spear, the arms being connected to a common pillar which is reciprocated for example, by a crank which is in turn reciprocated by a rotating wheel through a connecting rod, the connecting rod being secured to the wheel by a self-aligning roller hearing so as to take-up the arcuate movement of the crank end.

It will be appreciated that with such a drive the only parts which are moving at spear speed are the spears themselves and the ends of the radially extending arms. This leads to a significant reduction in the weight of parts being reciprocated as compared with a straight line spear movement and consequently to an increase in speed of operation (for example from 210 picks per minute with straight line spear movement to 300 picks per minute) and/or a reduction in the power needed to drive the loom.

The means for holding and cutting the weft loops at each side of the loom when single pick cloth is being woven, or the pins and deflectors when double pick cloth is being woven, the means for changing the shed and the general arrangement and design for the spear heads, including the grippers may be essentially similar to those described in the specifications of our US. Patent No. 2,816,576. The reed and heddles are arranged on an arc and the warp threads pass over a curved rail between the beam and the heddles, the curve of the rail is designed so as to maintain an even spread of warp yards entering the heddles and reed and thence to the fell of the cloth.

As cloth is woven in an arc the weft threads will extend in an are relatively to the warp threads and this bias in the cloth has to be subsequently removed, by the use of a curved cloth straightening member e.g. a roller or rollers or a stationary curved member perhaps having rotatable ends preferably arranged so that the cloth passes thereover before being wound on the takeup roller, the curve of the member which is preferably but not necessarily in a vertical plane, being made such that the distance from the fell to a point in the cloth path after the member, is equal for all positions across the width of the cloth. The member thus compensates for the curve or bias put into the cloth during weaving. Alternatively the cloth straightening member could be located apart from the body for example in a separate cloth straightening machine.

The member preferably comprises a number of rollers each individually rotatably mounted, the outermost roller positioned to engage the edge portions of the cloth being provided with spikes, pins or other cloth gripping means or there being an associated roller provided with such means so that the edge portions of the cloth are held relatively to the centre portion.

A weft yarn reservoir as described in the specification of our co-pending US. application No. 625,480, filed Mar. 23, 1967, may be employed. Due to the arcuate arrangement of the spears the weft yarn can be led to the spears from a point adjacent the centre of the are thus obviating the need for means to take-up slack weft yarn which occurs at certain intervals of a yarn laying cycle if the spears are moving in a straight line motion.

An embodiment of a loom in accordance with the invention will now be described by way of example with reference to the accompanying diagrammatic drawings in which:

FIGURE 1 is a plan view of the loom with parts thereof omitted for clarity;

FIGURE 2 is a side elevation partly in section, taken approximately on the centre line of the loom, and

FIGURE 3 is a diagram showing, to a larger scale than FKIGURE 2, a part of the path of the cloth after this has been woven.

Warp threads are led from the warp beam 2 (see FIGURE 2) over a guide roller 3 and over a curved rail 4, the curve of which is designed so as to maintain an even spread of warp yarn entering heddles 6 and a reed 8 and thence to the fell of the cloth, the heddles and reed being arranged in an are having its centre at the point 10. The roller 3 acts to maintain the warp threads in a substantially constant position on the curved rail 4 despite the changes in the diameter of the beam 2 which occur lduring weaving.

Weft yarn W is drawn from tag ended supply cones 12 at each side of the loom (only those at the left-hand side being illustrated in FIGURE 1 for clarity) and is introduced into a tubular yarn reservoir '14 by means of an air jet issuing from the nozzle 16 in a manner described in detail in the specification of our copending US. application No. 625,480, filed Mar. 23, 1967.

The weft yarn issues from the inner end of the reservoir through an elbow 17 (see FIGURE 2) and along a passage 18 in radial arms 20, 22 and is then inserted through the warp shed from opposite sides thereof by weft inserting needles or spears 24, 26 respectively (the radial anm being in section so that only arm 22 and spear 26 are shown in FIGURE 2).

The spears are arcuate in form and are reciprocated so as to follow each other in the same path across the warp shed, the warp threads being she'dded progressively across the loom in the space between the heads 31, 30 of the two spears as they pass through the warp threads so that the weft yarns laid by each spear respectively are inserted in different sheds. Cutters are provided at each selvedge for automatically severing loops of weft, laid in the warp she'd of the spears around pins 31 at the selvedge edge of the cloth, the spear hea'ds being provided with grippers (not shown) to enable the spears to carry severed ends of the loops through the warp shed. Further details of suitable pins, cutters, their drive and the general weft laying cycle and of the arrangement of the loom parts can be ascertained from the specification of our US. Patent No. 2,816,576.

If desired the movement of the spears and of the pins and cutters can be that described in the specification of our co-pending US. application Ser. No. 625,480.

The inner end of each spear 24, 26 is mounted at the outer end of the arms 20, 22 respectively and the weft yarn W passes through passages 32 along the length of the spears, the yarn may be assisted by means of a further jet of air issuing from a nozzle 34 in the manner described in the specification of our co-pending US. application No. 625,480.

The radially extending arms 20, 22 are mounted on a tubular shaft 36 located at the centre of the arc and reciprocated by means of a lever 38 and connecting rod 40, the crank being connected to the connecting rod by means of a universal bearing 42. As the bearing 42, at the outer end of the crank 38, moves in an arcuate path the connecting rod 40 also has an arcuate movement and its outer end is therefore connected to a drive wheel 44 by means of a standard self-aligning roller bearing 46. The wheel 44 is driven by a belt drive or the like (not shown) and on rotation of the wheel, the crank arm 38 4 and hence the radial arms 20, 22 are reciprocated in an arcuate path.

The wheel spindle 48, which is mounted in bearings 50, carries a gear 52 at its outer end meshing with a corresponding gear 54 connected to a shaft 56 to transmit a drive to other parts of the loom e.g. the pin and cutting mechanism. For the reason explained in our US. Patent No. 2,816,576 this shaft should be driven at half the speed of the drive for the spears and this can be arranged for by the gearing 52, 54. The hed'dles 6 are also driven from the shaft 56 through levers 57.

The shaft 56 carries a further gear wheel 58 meshing with a gear 60 on one end a shaft 62 journalled at 64. The other end of the shaft 62 carries a chain wheel 66 driving a corresponding wheel 68 on a cam shaft 70. The shaft 70 extends to a position adjacent the cloth selvedge and carries two earns 72 in a box 74 acting to operate through linkage 76 the pin 31 and cutter which is formed integrally with the pin, at the correct times during the weaving cycle.

The drive for the earn shaft 70 for the left hand selvedge pins and cutter is not shown in the drawing but is also taken from the shaft 56.

As the arms 20, 22 reciprocate, the spears 24, 26 are driven simultaneously across the warp shed in close succession and act to lay weft yarn in two sheds, the weft being drawn from the reservoirs .14 as and when required during the laying cycle. As the weight of parts moved at the speed of the spears is small e.g. only the outer ends of the arms 20, 22 the spear speed can be high and it can be arranged for the spears to lay about three hundred picks of weft per minute. This is significantly greater than is the case of straight line spear movement as described in US. Patent No. 2,816,576. The arms 20, 22 can be made light by forming a series of holes through them.

As the weft yarn passes along the arms through the passages 18 from a point adjacent to the centre 10, the length of the weft path is substantially constant during a laying cycle (thus eliminating the necessity for com pensating devices).

The width of cloth being woven can be varied very simply by alteration of the position of the self-aligning bearing assembly 46 so that the throw of the arms 20, 22 is altered. The position of pinning and cutting mechanism (not shown) is also made adjustable to correspond with the extent of spear travel.

The grippers in the spear heads (not shown) can be driven by means of a drive comprising torsion rods (not shown) extending down the arms 20, 22 from the central shaft 36, and then along the length of the spears, the torsion rods themselves being twisted by a mechanism extending up the central shaft.

It will be appreciated that as the cloth is woven in an arc the weft threads lie in a curve across the cloth. This is due to the fact the spears are reciprocated in an arcuate path about the axis 10 which is perpendicular to the mean position of the warp shed at the cloth fell along the arcuate path, the plane of the mean position being the disector of the angle between the upper and lower warp threads when these are opened to form a shed through which the spear passes to lay weft threads (in other words the bisector of the angle the apex of which is indicated at X in FIGURE 3). This results in a cloth bias which is removed by means of curved cloth straightening rollers 78 over which the cloth passes prior to being wound on the take-up roller 80 (see FIGURES 2 and 3). The cloth straightening rollers are formed in a number of small sections freely mounted on a common curved shaft the outer rollers being provided with pins or spikes so as firmly to grip the selvedge of the cloth.

The common curve of the assembly or rollers is adjustable so as to remove the bias in the cloth. This is achieved when the curve is such that the distance from the fell (point X in FIGURE 3) to a point Y in the cloth path after the straightening rollers and prior to being wound on the take-up roll, is equal for all positions across the cloth. In the loom shown in the drawings the rollers are curved in a vertical plane but the curve could be arranged horizontally provided that the curve in each case is sufficient to remove the bias already in the cloth due to the arcuate movement of the spears.

After passing over the straightening rollers the cloth passes over a number of guide rollers 82 (see FIGURE 2) prior to being taken up on the take-up roller 80.

The loom takes up less space than a conventional straight loom due to its arcuate formation and can carry a larger cloth roller without sacrificing any floor space. Further, due to the fact that both the beam 2 and roller 80 are located beneath the plane of the spears a most compact and etficient arrangement is provided.

In Order to provide accessability for various parts of the loom and to enable a larger take-up roller to be used, it has been found desirable to slope the plane of the working parts of the loom at an angle of about to the horizontal as can be clearly seen from FIGURE 2.

As the take-up roller 80 is located behind the beam 2 which is at the front of the loom, cloth is woven away from an operator positioned at the front of the loom. This arrangement provides easy access to the warp and weft threads so as to make fault finding and repair simple and quick.

I claim:

1. A loom of the type in which two weft yarns are carried into a warp shed from opposite sides from stationary Weft supplies thereof by reciprocated spears which follow each other across the warp shed and in which the warp threads are shedded progressively across the loom between the said spears as they pass between the warp threads so that the weft threads can be laid in different sheds wherein the spears are arcuate and reciprocated in an arcuate path about an axis which is substantially perpendicular to the plane of the mean position of the warp shed at the fell along the arcuate path so that weft threads inserted into the warp lie in the cloth in an arc.

2. A loom as claimed in claim 1 in which supports for both a beam and a take-up roll are provided located beneath the plane containing the spears.

3. A loom as claimed in claim 2 in which the beam and take-up roll supports are so arranged and driven that the cloth when woven is moved in a direction away from the front of the loom.

4. A loom as claimed in claim 3 in which the spears are reciprocated in a plane extending downwardly at an angle to the horizontal from the rear to the front of the loom.

5. A loom as claimed in claim 4 in which the spears are reciprocated in a plane extending at an angle of about 20 from the horizontal.

6. A loom as claimed in claim 2 in which the cloth path includes a portion extending downwardly beneath the spears.

7. A loom as claimed in claim 2 in which heddles are arranged on an arc, the warp threads passing over a rail between the beam and the heddles, the rail being designed to maintain an even spread of Warp yarns entering the heddles and reed.

8. A loom as claimed in claim 1 including a curved cloth-straightening member to remove from woven cloth the bias which is present due to the fact that the cloth is woven in an arc, the curve of the member being such as to allow the distance from the fell across the width of the fabric along any one warp thread to a point in the cloth path beyond the member, to be equal.

9. A loom as claimed in claim 8 in which the curved cloth straightening member comprises a stationary member having rotatable ends.

10. A loom as claimed in claim 8 in which the curved cloth straightening member comprises at least one roller arranged on an arcuate pivot.

11. A loom as claimed in claim 10 in which the cloth straightening member comprises a number of rollers each independently rotatably mounted on a curved pivot, the outermost rollers designed to engage the edge portions of the cloth being provided with cloth gripping means so that the edge portions of the cloth are held relatively to the center portion.

12. A loom as claimed in claim 10 in which the curve of the cloth straightening member is in a vertical plane.

13. A loom as claimed in claim 1 in which the spears are driven by a drive comprising, for each spear, a radial- 1y extending arm, the arms being connected to a common pillar at the center of the arcuate path of the spears.

14. A loom as claimed in claim 13 in which the pillar is reciprocated by a crank which is reciprocated in turn by a rotating wheel through a connecting rod, the connecting rod being secured to the wheel by a self-aligning bearing so as to take up the arcuate movement of the crank end.

15. A loom as claimed in claim 14 in which means are provided to alter the position of the pivot point of the crank so as to vary the width of the cloth being woven.

16. A loom as claimed in claim 1 having a weft yarn reservoir extending radially outwardly from the center of the arcuate path so that weft yarn can be led to the spears from a point adjacent the center of the arc.

References Cited UNITED STATES PATENTS FOREIGN PATENTS 681,610 10/ 1952 Great Britain.

HENRY S. JAUDON, Primary Examiner.

US. Cl. X.R. 139123, 292 

